At the end of my tether with gear shifting issue

CreadanLady · 19-10-2022 11:15am

Ah man, that chainring is absolutely knackered worn. The teeth are worn on the forward face. You see how they slope more on the forward face than on the back. This causes the chain to rise up on the tooth when under strain and it will pop off.

G1032 · 19-10-2022 11:45am

https://www.boards.ie/discussion/comment/119764370#Comment_119764370

Thanks! Everyday is a learning day.

They didn't last p!ssing time so really. Can't find when I ordered those but can't have been much more than 10k or 12k km ago and I keep the drive train v clean and NEVER let a chain wear below the 0.75m point. Not a great advert for FSA chainrings.

Just to clarify what you mean so I will know for again, do you mean that the slope forward at point 1 in the pic below is much more pronounced than the slope backwards on point 2 on the picture?

smacl · 19-10-2022 12:36pm

https://www.boards.ie/discussion/comment/119757965#Comment_119757965

As you move through the cassette the chain line changes a bit which can cause this, same way that you get front derailleur rub only when in top or bottom cogs on the cassette.

hesker · 19-10-2022 1:02pm

https://www.boards.ie/discussion/comment/119764739#Comment_119764739

I was more thinking that the chain would get jammed by the inner face of the FD as opposed to how the chain would move in the first place. But I guess as soon as it grabs on the small ring it will push the RD in momentarily.

All a bit redundant anyway as it does look like a well worn chainring is the culprit.

smacl · 19-10-2022 2:06pm

https://www.boards.ie/discussion/comment/119764502#Comment_119764502

I could be wrong but I'm not sure chainring teeth are entirely symmetrical new, see stock picture below. It would make sense that the side grabbing the chain has a steeper angle to the crank than the other side. It would be interesting to see if this is the case with your new one.

G1032 · 19-10-2022 2:45pm

Hmmm. I hope it's the chainring cos I'm totally at a loss otherwise as to what's causing the issue.

smacl · 19-10-2022 3:43pm

https://www.boards.ie/discussion/comment/119765675#Comment_119765675

Looking at your first photo, assuming the chain is not coming into contact with the front derailleur it looks like the chain line from the bottom of the chain ring going towards the rear derailleur cage is iffy. I know you've checked the rear mech hanger but I'd be looking at it again as a very small bend there would be magnified by the time you reach the rear mech cage where the chain enters. Hopefully the new chain ring does the job and I've got this wrong, if not, I'd change the rear mech hanger as it is cheap enough part and eliminates this as a possible cause.

hesker · 19-10-2022 4:30pm

If you have a read of Sheldon Brown he shows how the wear pattern arises and can cause the chain to ride up on the chainring.

The photo above is typical of a worn chainring.

G1032 · 20-10-2022 10:05am

I found the receipt for the chain ring. Shipped May 10th 2021.

Looking back through Veloviewer and filtering for that Cannondale I can see I've done 11,904km on the road on that bike since then. Never use that bike on the turbo or in bad winter weather. Since this issue started some months ago it's safe to say I've done not much over 10,000km on that chainring.

That's shocking tbh. Such poor quality. Never did a worn chain get anywhere near it and the chainrings always kept clean.

What's worse is I've gone and ordered FSA chainring again.

Did no research on the last ones (or the new order either) but it seems the Omega rings pictured above are the bottom of the barrel in FSA. Lesson learned. I'm pretty sure (but open to correction) that it's Omega rings that were supplied with the bike.

New ones ordered are Gossamer which are one notch above. Let's see how they go.

smacl · 20-10-2022 1:39pm

Was looking to change chainrings on my Ultegra 6800 group but big rings not in stock anywhere, so just doing small ring, cassette and chain. Haven't changed the chain rings since getting the bike over 10 years ago so a bit overdue. I don't do anything like the distance you do but the occasional bit of gravel riding tends to murder chains. I tend to go through a couple of chains a year, so go with the cheaper SRAM ones, and tend to get a couple of years out of a cassette (105). Shocked how much the price difference between Wiggle and Bike-Discount has crept up in recent times, don't think I'll be using Wiggle or CRC anytime again soon.

Les than two years out of a chain ring seems pretty terrible.

magicbastarder · 20-10-2022 1:44pm

FWIW decathlon have about half a dozen 105 cassettes in stock ATM, 11-28, €55 each. which seems like a decent price.

smacl · 20-10-2022 2:38pm

https://www.boards.ie/discussion/comment/119770425#Comment_119770425

Very competitive, 11-34 in Bike Discount was €58.82, Wiggle €69.92

G1032 · 21-10-2022 5:05am

https://www.boards.ie/discussion/comment/119770395#Comment_119770395

I have a 53/39 105 11spd on another bike with easily 20000 km plus 4 years of turbo on it and it looks new. (Although I didn't think the FSA was worn so what do I know.🙈)

G1032 · 24-10-2022 5:44pm

https://www.boards.ie/discussion/comment/119757661#Comment_119757661

New 53T chain ring arrived. Old and new photos below 🙈. Mega difference.

G1032 · 24-10-2022 8:10pm

I've been looking at the chain line and comparing to another bike. It seems very severe on this Cannondale. It's a 54cm CAAD12.

What do ye think?

G1032 · 24-10-2022 8:37pm

Had another look. I'm not sure what the criteria is here but when in the middle of cassette and in the big ring the chain is straight.

magicbastarder · 24-10-2022 8:40pm

you're badly cross chained in that photo anyway, not a gear you'd be advised to use regularly.

G1032 · 24-10-2022 8:51pm

https://www.boards.ie/discussion/comment/119788749#Comment_119788749

Agreed. I can use it and without chain rub but just because I can doesn't mean I should 🙈

CramCycle · 24-10-2022 11:53pm

It's grand, unless it's making running noises, don't worry about it. People over estimate the f all difference cross chaining makes to wear for most cyclists.

CramCycle · 24-10-2022 11:54pm

Also the colour of your frame is magnificent.

standardg60 · 25-10-2022 12:15am

Cadburys someone said earlier, it is nice

iwillhtfu · 25-10-2022 11:12am

Reading through that briefly there I'd put it down to user error to some degree. The face of the chain ring is badly worn, I'm not sure I've seen one that bad before.

Take a look at your front mech and make sure it's indexing out far enough to not cause any chain rub which could be the reason for the wear on the chain ring if it's not allowing the chain to move out far enough. Obviously as the outer wears on the chain ring then it will allow the chain to ride up onto the teeth an inevitably fall onto the inner ring.

Also embrace the inner ring, the amount of lads I see in a 53-25 or greater on some spins is ridiculous.

magicbastarder · 25-10-2022 11:32am

https://www.boards.ie/discussion/comment/119789519#Comment_119789519

as mentioned by iwillhtfu though, cross chaining does imply failure to use the small ring (or vice versa); which will increase wear because you're generally expecting one ring to take most of the load instead of sharing it between the two.

standardg60 · 25-10-2022 8:18pm

https://www.boards.ie/discussion/comment/119790502#Comment_119790502

Actually got chastised for cross chaining from some club emblazoned know it all on a charity cycle recently. I have a really low cadence preference so the big ring suits me, and would only be cross chaining for short inclines.

If i have to replace the big chainring more often so be it, F the begrudgers :-).

iwillhtfu · 25-10-2022 8:24pm

https://www.boards.ie/discussion/comment/119792977#Comment_119792977

Sure knees are overrated anyway 🤷‍♂️ I mean who will need them when they're older😂

standardg60 · 25-10-2022 9:02pm

https://www.boards.ie/discussion/comment/119793010#Comment_119793010

I am old!

Old habits die hard😁

CramCycle · 26-10-2022 7:50am

https://www.boards.ie/discussion/comment/119790577#Comment_119790577

True but in the grand scheme of things with modern chainsets, I imagine the difference is not of great concern for most riders.

07Lapierre · 26-10-2022 1:37pm

Is it a compact chain set? I find a compact “encourages” cross chaining as the difference between the large and small chainrings is significant. Example…it takes effort/ thought to change from a 50x25 to something like a 36x14 or whatever. Also if you believe the “experts”, a large sprocket/large chainring is more efficient than a small chainring/small sprocket.

JMcL · 26-10-2022 5:18pm

Take a look at your front mech and make sure it's indexing out far enough to not cause any chain rub which could be the reason for the wear on the chain ring if it's not allowing the chain to move out far enough

I would imagine in that case the derailleur cage would disintegrate before anything. I do remember this happening on a bike I had when I were a lad - back when the world wide web was a mere glint in Tim Berners Lee's eye, books on bike maintenance in rural Donegal were hard to come by and, more pertinently, I hadn't the first clue about how to go about adjusting a front mech (I still hate it even though I know how to do it now). I don't remember it rubbing too badly (your honour), but the chain ate through the outer plate of the cage in no time. When I replaced it, probably by trial and error, I learned a lot more about adjusting mechs!

G1032 · 26-10-2022 8:42pm

https://www.boards.ie/discussion/comment/119795262#Comment_119795262

Semi compact, or was a semi compact.. It's a 53/36 now 😂.

I use the 36 regularly though, especially where I'm trying to keep the watts constant and cadence high on rolling roads.

Also do my fair share of cross chaining but absolutely without question still spend more time in the small ring than most other I know.

Winter bike has a 53/39 which I much prefer. Can't say I've ever noticed a difference between the 52 and 53 but I find the difference between the 36 and 39 to be huge

At the end of my tether with gear shifting issue

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